1. Field of the Invention
The present invention relates to the field of testing integrated circuits; more specifically, it relates to a method and circuit for testing regulated power supplies in integrated circuits.
2. Background of the Invention
Modern integrated circuits can include the capability to regulate voltage domains in both analog and digital applications. To date, the testing of the circuits generating regulated voltages in these applications has been limited. In analog applications, the regulated voltage generating circuit is often not directly tested and is considered “good” if the circuits it supplies function. In digital applications, often the voltage at a single point in the power distribution network is measured, but with the logic circuits inactive.
These test methods do not insure that the regulated voltage generating circuit has adequate current margin under operating conditions or, in the case of multiple voltage generating circuits, if one or more are not operating properly.